The present invention is generally related to sensing and measuring devices. The illustrative embodiments of the present invention are related to electronic position sensing devices.
Manufactured parts are often required to be in within certain tolerances. Individual parts are frequently measured to determine whether or not their dimensions are accurate before they are assembled to other parts.
The problem of determining the dimensional accuracy of a part is often complicated by the fact that measuring equipment is expensive for the manufacturer to purchase and maintain and difficult for an operator to use. For example, coordinate measuring machines, or CMM machines, are sometimes used to measure manufactured parts for dimensional accuracy. Although coordinate measuring machines are accurate, they are also expensive, large and not portable, difficult for the worker to learn to operate, and time-consuming to set up and use. Ferro arms are also sometimes used to verify the dimensional accuracy of parts, but are also expensive, large, difficult to learn to operate, and are time-consuming to use when taking a series of measurements on a series of parts.
The problem of checking the dimensional accuracy of parts is often further complicated by the fact that portions of a part to be checked for dimensional accuracy may move or flex when a measuring instrument contacts the part. This movement of the part due to contact with the measuring instrument can result in measuring inaccuracies.
The illustrative embodiment of the present invention provides an electronic measuring device that includes a housing having an exterior surface configured and arranged to be removably secured within a support member such that the housing can be removably replaced in the support member. An electrically conductive probe is coupled to the housing and is configured and arranged to extend through the support member and move between a position in contact with a workpiece and a position out of contact with the workpiece. An indicator and a power source are disposed within the housing. A circuit electrically couples the probe to the indicator and to the power source such that when the probe is out of contact with the workpiece, the circuit is open and no power is supplied from the power source to the indicator and such that when the probe contacts the workpiece, the circuit closes to supply power from the power source to the indicator to send a signal to the operator that the probe is in contact with the workpiece.
The illustrative embodiments also provide a measuring assembly comprising a fixture for removably holding a workpiece to be measured, a support member positioned a predetermined distance from the fixture and an electronic measuring device. The measuring device includes a housing having an exterior surface configured and arranged to be removably secured within the support member such that the measuring device can be removably replaced in the support member. An electrically conductive probe is coupled to the housing for movement between a position in contact with the workpiece and a position out of contact with the workpiece. An indicator and a power source are both disposed in the housing. A circuit electrically connects the probe to the indicator and to the power source such that when the probe is out of contact with the workpiece, the circuit is open and the power source does not provide power to the indicator and such that when the probe contacts the workpiece, the circuit closes such that power is provided to the indicator to activate the indicator to send a signal to the operator of the measuring device that the probe is in contact with the workpiece.
The illustrative embodiments of the present invention further provide methods for measuring a workpiece using a measuring device including providing a fixture for removably holding a first workpiece to be measured, providing a support member positioned a predetermined distance from the fixture and providing an electronic measuring device. The measuring device includes a housing having an exterior surface configured and arranged to be removably secured to the support member, an electrically conductive probe coupled to the housing for movement between a position in contact with the first workpiece and a position out of contact with the first workpiece, and an indicator and a power source. Both the indicator and the power source are disposed within the housing. The example method also includes providing a circuit electrically connecting the probe, the indicator and the power source such that when the probe is out of contact with the first workpiece, the circuit is open and no power is supplied from the power source to the indicator and such that when the probe contacts the first workpiece, the circuit closes and power is supplied from the power source to the indicator to signal the operator of the measuring device that the probe is in contact with the first workpiece. The method also includes removeably holding the first workpiece in the fixture, removably securing the measuring device into the support member and moving the probe into contact with the first workpiece until contact is made and the indicator sends the signal that contact with the first workpiece is achieved. The method next recites removing the first workpiece from the fixture and inserting a second workpiece into the fixture for measuring.
Other aspects, features and advantages of the present invention and the illustrative embodiments will become apparent from the following detailed description, the accompanying drawings, and the appended claims.